Everything you need is a web-server with PHP 5.5 or later and a MySQL-Database.
The following PHP extensions must be activated:
session, exif, mbstring, gd, mysqli, json, zip
To use Lychee without restrictions, we recommend to increase the values of the following properties in php.ini:
max_execution_time = 200
post_max_size = 100M
upload_max_size = 100M
upload_max_filesize = 20M
memory_limit = 256M
You might also take a look at Issue #106 if you are using nginx or in the FAQ if you are using CGI or FastCGI.
The easiest way to download Lychee is with git:
git clone https://github.com/electerious/Lychee.git
You can also use the direct download.
Change the permissions of uploads/, data/ and all their subfolders. Sufficient read/write privileges are required.
chmod -R 750 uploads/ data/
Open Lychee in your browser and follow the given steps. If you have trouble, take a look at the FAQ.